GPRC5A and lung adenoma: The functional relevance of RAI3 expression in benign lung was previously highlighted by earlier studies demonstrating that GPRC5A-knockout mice spontaneous develop lung adenomas and adenocarcinomas (Tao et al. 2007) and that loss of heterozygosity of chromosome 12p13 is a common alteration in NSCLCs (Takeuchi et al. 1996; Grepmeier et al. 2005).